1. Field
Embodiments of the present disclosure relate to a drone using a coaxial counter-rotating rotor, more particularly, a drone which may have a foldable propeller for easy keeping and which may also minimize damage to the propeller and other components.
2. Background
Helicopters are aircrafts which fly by an aerodynamic lift generated from a rotor rotated by an engine. Such helicopters may be classified into conventional helicopters having a size allowing a pilot or a pilot and one or more passengers and unmanned helicopters, i.e., drones having a relatively small size. With recent development of wireless communication and mobile terminals, techniques using functions of a drone and a mobile terminal combinedly are being developed.
For instance, examples of such functions include data and voice communication, image and video capturing which uses a camera, and voice recording and etc. Some terminals may implement an additional function of electronic games (i.e., video games) or a function for a multimedia player.
As having diversified functions, such a drone may be realized as a multimedia player having combined functions including image or video capturing and broadcasting signal receiving.
Especially, in case a camera is installed in the drone, more functions may be implemented. The drone having the camera may be used in lifesaving as well as reconnaissance.
As a driving manner for flying a drone there are a coaxial counter-rotating manner for a conventional drone has two coaxial rotors and a multiple-axial rotating manner for a drone having multiple rotors rotating on different axes to generate an aerodynamic lift. However, such a conventional drone has a propeller which cannot be folded and a volume of the conventional drone cannot be reduced. The not-foldable propeller need protecting from external circumstances and it requires an auxiliary members. The requirement of the auxiliary members results in increase of an overall drone weight and a higher power is required to keep and maintain the aerodynamic lift.